The class of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon is known in the art. An early production of such polymers is disclosed by Nozaki, e.g., U.S. Pat. No. 3,694,412, who employed an arylphosphine complex of palladium moieties as catalyst and certain inert solvents.
More recently, the class of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon has become of greater interest in part because of the greater availability of the polymers. These polymers, often referred to as polyketones or polyketone polymers, have been more recently produced by processes disclosed by a number of published European Patent applications including 121,965, 181,014, 213,671, 257,663 and 345,847. The process typically involves the use of a catalyst composition formed from a compound of palladium, cobalt or nickel, the anion of a strong non-hydrohalogenic acid and a bidentate ligand of phosphorus, arsenic, antimony, nitrogen or sulfur. The resulting polymers arc relatively high molecular weight materials having established utility as premium thermoplastics in the production of shaped articles such as containers for food and drink by processes which are conventional for thermoplastic polymers.
The production of these polyketone polymers suffers, however, from a problem that is common to the production of many if not most polymeric materials. When practiced on a large or a commercial scale, the production of the linear alternating polymers results in the formation of certain proportions of polymer that is not easily removed from the polymerization reactor and remains adhered to the internal surfaces of the reaction vessel. Methods have been proposed to reduce the degree of this reactor fouling including polishing or coating the internal surfaces of the polymerization reactor prior to polyketone production or the inclusion of particulate material in the polymerization mixture. It would be of advantage, however, to provide an improved process for the production of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon which exhibits a reduced or lessened degree of reactor fouling.